How do I fix my fuel trim Bank 2?
What repairs can fix the P0173 code?
- Replacing the mass air flow sensor.
- Replacing the fuel pressure regulator.
- Replacing the intake manifold gaskets.
- Repairing or replacing the engine air filter intake system.
- Replacing a vacuum line connected to the throttle body.
- Repairing a leaking brake booster.
What causes fuel trims to be high?
Why are the fuel trim numbers high? If LTFT or total fuel trim is greater than plus 10%, the PCM thinks the air/fuel ratio is too lean and it’s adding fuel to bring STFT control to the correct range. This presents three possibilities: Unmeasured air is reaching the combustion chambers.
Does O2 sensor affect fuel trim?
If a longer-than-normal injector pulse width is required to maintain the desired oxygen sensor signal, the ECM/PCM displays an increased fuel trim value in its datastream. Of course, accurate fuel trim values are based on a properly functioning oxygen sensor.
What does oxygen sensor Bank 2 mean?
Bank 2 is the set of cylinders that does not have number one cylinder. Sensor 1 is the sensor before the catalytic converter which the computer uses to make fuel ratio calculations. Sensor 2 is the sensor that comes after the catalytic converter and is mainly used for onboard emissions testing.
What does the 2nd O2 sensor do?
Oxygen sensor 2 is the downstream oxygen sensor in relationship to the catalytic converter. It measures the air-fuel ratio coming out of the catalytic converter to ensure the catalytic converter is functioning properly.
What controls short fuel trim?
Short-term fuel trim happens as a result of changes in the oxygen levels of exhaust gases. An oxygen sensor monitors the flow and generates a signal that is proportional to the oxygen levels in the gases.
When should I reset fuel trims?
Any time you’re tuning VE or MAF, you should force open loop and disable the open loop STFT. After that, flash the file, start the engine and reset the trims.
How does the ECM/PCM know when to adjust fuel trims?
During the course of watching the upstream O2 sensor, the ECM/PCM also watches the downstream sensor for indications that the mixture is too lean – and if the upstream O2 sensor on that bank becomes unreliable, the ECM/PCM will actually begin to adjust fuel trims based on rear O2 sensor input.
Why does fuel trim increase when pulse width is longer than normal?
If a longer-than-normal injector pulse width is required to maintain the desired oxygen sensor signal, the ECM/PCM displays an increased fuel trim value in its datastream. Of course, accurate fuel trim values are based on a properly functioning oxygen sensor.
What is the LTFT for bank 1 and Bank 2?
If the LTFT for bank 1 is 20% and the LTFT for bank 2 is 3%, the source of the problem is associated with bank 1 cylinders only. The diagnosis should focus on factors related to bank 1.
What should I do if my fuel trim is low?
A useful diagnostic tool is to determine if the fuel trim problem exists in more than one engine operating range. Fuel trim should be checked at idle, at 1,500 rpm and at 2,500 rpm. In addition to these no-load checks, drive the vehicle at various steady load conditions and watch for fuel trim variation.